Synthesis of novel Schiff base metal complexes with reactive groups and their catalytic property for hydrogen peroxide decomposition

Abstract

A novel water soluble azo Schiff base ligand containing crosslinking reactive groups (A), 3,5-bis [(2-hydroxy-4′-sodiumsulphatoethylsulphonyl) azobenzene- methyneimino]-benzoic acid (BHSABA), and its complexes with Mn2+, Cu2+, Co2+, were synthesized and characterized by elemental analysis, Fourier transform infrared (FT-IR) and proton nuclear magnetic resonance (1HNMR) spectroscopy. The Schiff base ligand and its complexes had excellent water solubility. Two reactive groups, p-[(2′-sulphatoethyl) sulphonyl groups, were able to form covalent bonds with biomass, such as cellulose, chitosan and so on, to obtain functional material. Ultraviolet–visible (UV-vis) electronic absorbance and fluorescence spectra of the ligand having azo conjugated system and of the metal complexes were measured. The catalytic activity of the ligand and the complexes for H2O2 decomposition were also investigated. The results show that the fluorescence spectra of the complexes, Co2A and Mn2A, had increased fluorescence phenomena. They had strong catalytic activity for H2O2 decomposition. When the concentration of manganese complex, Mn2A, was 5 mg/l, H2O2 decomposition nearly finished in 40 min at 40℃. The order of catalytic activity of three complexes for H2O2 decomposition was Mn2A > Co2A > Cu2A. The ligand itself had no noticeable catalytic activity for H2O2 decomposition. These novel water soluble Schiff base metal complexes with reactive groups have potential application in the H2O2 decomposition of water treatment fields.